Dual-Band Filtering Balanced-to-Unbalanced Impedance-Transforming Power Divider With High Frequency Ratio and Arbitrary Power Division

This paper presents a novel dual-band filtering balanced-to-unbalanced impedance transforming out-of-phase power divider using a simple admittance inverter with an extreme high frequency ratio and arbitrary power division, which is composed of stepped-impedance transmission lines. Based on the traditional transmission-line theory and ABCD/V matrix, the closed-formed analytical equations and complete design procedure are derived and provided for the filtering differential-mode transmission with high frequency ratio and good dual-band common-mode suppression. For demonstration, a designed prototype operating at 1 and 6.4 GHz are simulated, fabricated, and measured. The measured results agree well with the EM simulation perfectly.